Device for boring engine cylinders



L. V JOHNSON.

DEVICE FOR BOR ING -ENG|NE CYLINDERS.

APPLICATION FILED JULY 24.1920.

Patented Feb. 14, 1922.

2 SHEETS-SHEET I.

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Wu INVENTOR.

' 7 ATTORNEY! 2 UNITED STATES PATENT OFFICE.

LOUIS V. JOHNSON, OF FORT WORTH, TEXAS.

DEVICE FOR BORING ENGINE CYLINDERS.

' Application filed July 24,

To all whom it may concern.

Be it known that I, LOUIS V. JorrNsoN, a citizen of the United States, residing at Fort Worth, in the coi'lnty of Tanrant and State of Texas, have invented certain new and useful Improvements in Devices for Boring Engine Cylinders, of which the following is a specification.

This invention relates to devices for boringengine cylinders and more particularly toadevice for boring the cylinders of rotary engines of the type disclosed in my co-pending application filed July 6, 1920, Serial No. 3%,216. In enginesof this type embodying a rotor having radially shiftableor movable blades, which rotor is mounted eccentrlcally within the engine cylinder the inner surface of the wall of the cylinder does not describe a true cylindrical form but is of necessity oi an irregular shape, diametrlcally opposite portions of the wall being eccentric to the true axis of the cylinder whereas the intervening diametrically opposite portions of the wall are concentric to the said arms. It is my understanding that great difliculty has been experienced in boring cyl nders for engines of this type, and the primary object of the present invention therefore to provide a boring device which may be conveniently employed in any of the or: dinary forms of lathes, for the purpose of accurately, readily, and expeditiously boring cylinders of this type.

Another object of the invention is to so mount and construct the cutter and the support therefoiyin a device for this purpose, that, in the operation of the device, the work being acted upon will in a sense constltute tcmplet, and a portion of the support for the cutting tool will coact therewith in such a manner as to insure of correct and accurate cutting of the cylinder wall.

In the accompanying drawing:

Figure 1 is a verticaltransverse sectional view illustrating the device embodying the present invention in operation in boring a cylinder of the type above mentioned;

Figure 2 is a horizontal sectional View through the structure taken substantially on the line 22 of Figure 1; c

Figure 3 is a detail transverse Sectional view on the line of Figure 1;

Figure l is a perspective view illustrating one of the members of the device.

In the drawing, the numeral 1 indicates the work which is an engine cylinder of the Specification of Letters Patent.

Patented Feb. 14, 1922. 1920. Serial No. 398,631.

type heretofore mentioned, and in Figure l of the drawings this piece of work-is illustrated as disposed upon the adjustable bed 2 of any of the well-known types of lathes or boring machines, the work being preferably held in place by a band 3 disposed about the outer side of the cylinder and having threaded ends at which may be fitted through openings in the bed 2and which may have bolts 5 applied thereto for the purpose of tightening the band. In Figure 2 the numeral 6 indicates the face plate of the lathe or boring machine and 7 the usual center associated therewith. The numeral 8 indicat-es the center which is carried by the lathe carriage, and disposed between the centers 7 and 8 is a short shaft which is indicated by the numeral 9. The numeral 10 indicates a dog which is clamped to one end of the shaft 9 and which is engaged with the face plate 6 so as to provide for rotationof the shaft 9 with the said plate in the operation of the machine. The shaft 9 extends through the work 1 and carries and forms a part of the device embodying the invention.

In addition to the shaft 9, the device embodying the inventioncomprises a pair of counterpart cheek members indicated in general by the numeral llQwhich members are of circular form and provided with hub ,portions 12 keyed or otherwise secured, as at 13, upon the said shaft 9, the said members being secured together bycmeans of bolts let and when assembled constituting the head of the device. The check pieces 11 are formed in their inner faces with recesses 15 which extend diametrically of the said faces of the members and which terminate at their ends in slots 16 which open at their outer ends through the peripheries of the respective cheek members. lVhen themembersare assembled these recesses and slots register, as will be evident by reference to Figure 2 of the drawings. The tool holder of the'device is indicated in general by the numeral 17 and the said holder comprises a yoke 18 which is disposed slidably within the housing provided by the matching recesses 15 1 and which straddle the shaft 9. This yoke 18 is pro vided at its opposite ends with shank portions which are indicated one by the numeral 19 and the other by the numeral 20.

these portions projecting through the slots 16 in the manner clearly shown in Figure 1 of the drawing. The shank 191s formed with a longitudinally extending socket 21 in which is seated the tang of the tool indicated by the numeral 22. In order that the tool may be adjusted to project a greater or less distance at its cutting end beyond the end of the shank 19, an adjusting screw 23 is threaded through the inner end wall of the socket 21 and bears against the end of the tool tang 22, this adjusting screw being provided with any suitable kind of head 2e whereby it may be rotated, and the shank 19 being formed with a transverse opening or passage 25 receiving this head and permitting of access thereto. In order that the tool may be secured in its positions of adjustment, a set screw 26 is threaded through the outer end portion of the shank l9 and bears at its inner end against the upper side of the said tool.

The shank 20 of the tool holder 17 is preferably reduced upon its upper and under sides as indicated by the numeral 27, and fitted thereto is a nose piece indicated in general by the numeral 28. This nose piece comprises base portions 28 and a con necting portion 30 which is rounded at its outer end to form the nose. The nose piece is disposed with its base portions straddling the reduced end of the shank 20 and may therefore be adjusted longitudinally of the said portion of the shank. In order that the nose piece may be held in positions of adjustment, a set screw 31 is threaded to one of the base portions 29 and bears against the adjacent side of the reduced portion of the shank.

The shaft 9 is formed with a recess 31 which extends radially therein, and disposed to seat at one end within this recess is a coil spring indicated by the numeral 32, the spring hearing at its other end against the adjacent end wall of the opening in the yoke 18 or more specifically that wall which is located next adjacent the shank 20. The tendency of this spring is to yieldably hold the tool holder in a direction to retract the tool, and consequently movement of the tool holder in a direction to project the tool must be against the tension of this spring.

As previously stated, the device embodying the invention is designed for the purpose of boring the cylinders of engines of that type embodying a rotor having diametrically shiftable or slidable pistons and in which the rotor is mounted eccentrically within the chamber or bore of the cylinder, and from the preceding description it will be evident that the device of the invention operates somewhat in the manner of the rotor of such an engine. For example after it has been determined what position the axis of the rotor of the engine shall have with respect to the axis of the engine cylinder, the method of procedure in boring the cylinder block is as follows: The block is first formed with a cylindrical bore of predetermined dimensions, and is then secured upon the bed 2 of the boring machine. The device embodying the invention is then adjusted to working position and in this ad justment the axis of the shaft 9 is brought to identically the same position with relation to the true axis of the cylinder as initially bored, as it is intended the axis of the rotor of the engine shall bear to the axis of the engine cylinder. Then when the shaft is rotated, the tool 22 will be caused to operate Within the cylindrical bore initially formed in the cylindrical block, and the blade may be adjusted in an outward direction from time to time as required. Due to the eccentric location to the axis of the shaft 9 with relation to the true axis of the cylinder, the nose 30 will continuously contact the wall of the cylinder bore and as it rides over the portion of the wall of the bore which is nearer the axis of the shaft 9, will be forced in a radial direction thus projecting the cutter 22 to a greater or less distance. Thus when the tool holder 17 is in the position shown in full lines in Figure 3 of the drawings, the nose 30 will ride against a portion of the wall of the cylindrical bore and as the nose and the tool, in this position of the parts, extend on a line below the true axis of the cylinder bore, the bit of the tool will be caused to cut into the wall of the cylinder at a point chordally opposite the point engaged by the said nose. However as the parts reach the dotted line position shown in the said figure, and before and immediately after they reach this position, the distance between the nose 30 and the bit of the tool 22 will be less than the diameter of the cylindrical bore and as these elements will then be on a line extending substantially diametrically through the axis of the said cylindrical bore, the cutting end or bite of the tool will clear the wall. The device embodying the invention will of course be more or less continuously rotated, and the cutting tool 22 will be adjusted from time to time until finally the wall of the bore will have been brought to the required irregular curvilinear contour.

Having thus described the invention, what is claimed as new is:

1. In a device of the class described, a rotatable shaft, a head fixed upon the shaft for rotation therewith and interiorly chambered and provided at its periphery with oppositely located openings communicating with the chamber, a yoke shiftably mounted in the chamber and transversely of the shaft, a shank extending from one end of the yoke and through one of the said openings for the support of a cutting tool, a shank extending from the other end of the yoke and through the other opening, and

the yoke and through one of the said openings for the support of a cutting tool, a 15 shank extending from the other opening, a nose carried by the last-mentioned shank the walls of the openings in the head supporting and steadying the shanks of the yoke relatively close to their outer ends whereby to 20 prevent chattering of the tool, the shaft being recessed, and a spring seated at one end within the recess in the shaft and bearing at its other end against the inner side of that end of the yoke from which the last 25 mentioned shank extends.

In testimony whereof I aflix my signature.

LOUIS V. J OHNSON. [L. s] 

